FORSCHUNGSZENTRUM JÜLICHS’ MAGAZINE
1-1 9
Sleep well!
Fatigue impairs us – researchers investigate what happens in the brain
PLAYING WELL Chess experts think differently
FLASHING WELL Exploring the sun from inside the earth
PRODUCING WELL The unused treasures
of the paprika plant
Wow, listen!
No shiny metal. Instead, a pond pump hose and a white plastic funnel. On his hand-made tube trumpet, Jonathan Paschke can really play – the first bars of Beethoven’s “Ode to Joy” can easily be recognized. The nine-year-old schoolboy from the community
primary school Jülich-West found out, with precise frequency measurements and calculations, such as of tube length and pitch, how his trumpet kit sounds best. That brought him first place in this year’s regional competition “Schüler experimentieren”
(school children experiment) at Forschungszentrum Jülich in the physics section and ensured him a spot in the state competition.
Want to hear what the tube trumpet sounds like? You find the video at effzett.fz-juelich.de/en
Please touch!
Feeling on the smartphone:
computer model provides the basis.
26
Solar telescope underground
New data confirm previous findings about the energy
production of the sun.
29
SECTIONS
Editorial
4
Publication details 4
What are you researching right now?
21 Knowing-it-all
28 Thumbs up
31
Research in a tweet 32
NE WS
5
COVER STORY
Sleepless in Cologne
Lots of coffee, little sleep:
researchers want to find out how the brain reacts to that.
Benjamin Marschner volunteered himself as a test person.
8
RESE ARCH
How long does a neutron live?
Jülich physicists have come one step closer to the answer – thanks
to new mathematical methods.
16
Maxed out!
Unused leftovers of pepper plants contain valuable substances.
TaReCa wants to tap them.
18
Experts have better connected
For researchers like Robert Langner, chess is more
than just a game.
22
A bridge to Africa
Knowledge transfer supports sustainable agriculture.
24
Marcel Bülow (24-25), Forschungszentrum Jülich/Sascha Kreklau (title, 3 top left, 6 top left, 8-15, 18-19, 21, 27 top), Forschungs zentrum Jülich/
Ralf-Uwe Limbach (2, 3 bottom middle, 6 right, 17 top, 23, 32), BOREXINO Collaboration (29), CC BY-NC-ND/ www.weltderphysik.de (17 graphics), Diane Köhne (28 illustration with text), SeitenPlan GmbH (27 figures 1-2), all motifs mentioned below are from Shutterstock.com: Bloomicon (31 left), Guitar photographer (5 top), MaraQu (16-17 background), MoonRock (5 bottom), Nattika (3 top middle), perfectlab (7), Peshkova (4), Sentavio (26 illustration), SkyPics Studio (3 right, 30), spacezerocom (28 shad- ing), vchal (3 bottom left)
Contact: Corporate Communications, Tel: +49 2461 61-4661 | Fax: +49 2461 61-4666 | Email: info@fz-juelich.de effzett Forschungszentrums Jülich’s magazine, ISSN 1433-7371
Published by: Forschungszentrum Jülich GmbH | 52425 Jülich, Germany Conception and editorial work: Annette Stettien, Dr. Barbara Schunk, Christian Hohlfeld, Dr. Anne Rother (responsible under German Press Law) Authors: Marcel Bülow, Dr. Frank Frick, Christian Hohlfeld, Dr. Jens Kube, Katja Lüers, Dr. Regine Panknin, Philippe Patra, Tobias Schlößer, Dr. Bar- bara Schunk, Brigitte Stahl-Busse, Angela Wenzik, Erhard Zeiss Graphics and layout: SeitenPlan GmbH, Corporate Publishing Dortmund, Germany
Translation: Antje Becker, ROTPUNKT•Texte & Bild, Germany Images: Forschungszentrum Jülich (31 right), Forschungszentrum Jülich/
Publication details
the question of sleeping habits. But maybe you are not a bird at all.
Maybe you are a wolf, a lion, a bear or a dolphin. The US-American sleep researcher Michael Breus suggests this classification: the lion roars in the morning, full of energy, but falls asleep immediately in the evening, exhausted. In contrast, the wolf, who is grumpy in the morning, would rather go hunting in the evening. The dolphin is also active in the evening, but has a light and restless sleep. At noon, the bear hums with lots of vigour while at night, it slumbers particularly long and deep.
We sleep at different times and also need different amounts of sleep.
This becomes particularly clear when there is a lack of sleep, as our cover story shows: some people who are heavily tired hardly show any performance weaknesses, while others become extremely unfocused and agitated. Researchers from Cologne, Zurich and Jülich are inves- tigating what happens in the brain in the sleep laboratory. We visited them there.
Also, read about how stems and leaves from paprika plants can be used profitably, what we can learn from chess players, and how researchers receive messages from the sun deep inside a mountain.
We wish you an always alert mind and hope you enjoy reading!
Your effzett editorial team
You can access effzett on all devices – from smart phones to PCs.
Simply access it online:
effzett.fz-juelich.de/en Read the
online magazine now
There’s
even more!
Climate change is modifying the speed at which glaciers flow and transport ice into the sea.
Researchers use computer models to calculate this speed. A new theory by the Jülich physicist Bo Persson could help to improve these models. He has harnessed the sliding of glacial ice over rocky ground in formulas.
Among other things, they describe how water-filled cavities between the ice and the bedrock influence the sliding speed of a glacier.
– P E T E R G R Ü N B E R G I N S T I T U T E –
P H YSI C S
The gliding of glaciers
M AT E RI A L S RESE A R CH
New state in the crystal
The Greek scholar Thales of Miletus already knew about magnetic materials. But even more than 2,500 years later, they are still always good for a surprise. Researchers from Jülich, Poland and Japan have now
discovered a new multi-particle state in an iron crystal – they found it exactly where theorists from the Peter Grünberg Institute had
already predicted it.
– P E T E R G R Ü N B E R G I N S T I T U T E –
Climate researcher Prof. Andreas Wahner in an interview on the first World Climate Conference 40 years ago.
Read the full interview on our website:
fz-juelich.de/worldclimateconference
“Back then, we were joking:
if sea levels rise, we’ll be safe in
Bochum.”
62 per cent
– this level of electrical efficiency of a hight-temperature fuel cell “Made in Jülich” is a world record. No other unit so far has generated electricity more efficiently from hydrogen. What’s
special here: the reverse process can also take place in the fuel cell, that is, hydrogen can be
produced with electricity.
– I N S T I T U T E O F E N E R GY A N D C L I M AT E R E S E A R C H –
Gorilla glass is particularly break-proof and scratch-resistant. Smartphone displays made of this glass remain the majority of the time intact when falling from a height of
one metre. The formula for this success: the surface of the glass is tempered by heat treatment. Jülich researchers have developed a coating that transfers the principle of tempering to a transparent ceramic, thus doubling its resistance to breaking. Transparent ceramics are suitable as vision panels or for optical lenses,
because they are very heat-stable and focus light more than glass does.
– I N S T I T U T E O F E N E R GY A N D C L I M AT E R E S E A R C H –
Gorilla glass, a paragon
New addition:
high-power laser Vega
Vega pulsates with 1.4 trillion watts of power – which is about half of the world’s average power consumption.* It does so 1,000 times per second for
30 femtoseconds (0.000 000 000 000 03 seconds).
On average, its performance therefore corresponds to that of a 40-watt light bulb.
Vega enables the analysis of ultra-fast physical processes and the development of new materials for
information technology (e.g. for data storage).
It is part of the recently inaugurated Jülich laser laboratory JuSPARC.
Stay up to date!
From now on, our new email newsletter (in German) will provide you with a monthly overview of science,
people and projects at Forschungs- zentrum Jülich.
Subscribe here:
www.fz-juelich.de/juelich-news
NEW
* Global electricity consumption in 2016: 20,863 TWh, which is equivalent to an average power of 2.4 TW (2.4 trillion watts) Source: Electricity Information 2018, International Energy Agency
How do extreme weather events influence an energy system which is
predominantly based on renewable energies? Are local wind turbines more economical than a nationwide grid with offshore wind turbines? Researchers are looking for answers to questions relating to the energy revolution with the help of
model calculations on supercomputers.
In the current models, however, a single data node often represents a complete German state. Researchers from Jülich, Aachen and Erlangen-Nuremberg want to
change that: since the end of 2018, in the METIS project, they have been working on models and tools that allow detailed simulations of several decades. The federal
government supports METIS with more than € 1.8 million.
– I N S T I T U T E O F E N E R GY A N D C L I M AT E R E S E A R C H –
GO -A HE A D
Simulating the
energy revolution
Day 1
Arrival
He is not tired on this grey winter morning. On the contrary:
Benjamin Marschner is well rested on his way to the German Aerospace Center (DLR) in Cologne. For ten days, he wants to participate in a sleep study there. He is bringing his laptop and – as befits a passionate musician – his guitar. The 32-year- old cannot quite imagine what awaits him – even though he has received the extensive study conditions: “It’s essentially about how sleep deprivation affects my performance and what role coffee plays in it.”
Already two weeks before the start of the study, Marschner had to sleep nine hours at a time, was no longer permitted to drink coffee and alcohol and, above all, was not to eat any chocolate. “That’s what I miss most,” the music student admits.
But now he is first and foremost curious about his new home.
“Playing a little guitar, maybe writing one or two songs and sleeping in between,” he describes his idea.
Marschner registers at DLR’s main entrance and walks ten minutes across the extensive grounds to the laboratory. “Ac- tually a nice area,” he thinks on the way and looks forward to going for walks in the next few days.
Finally, his destination appears, majestically seated on a hill:
the futuristic-looking research centre “envihab” – lots of glass, even more white. The building is more reminiscent of a space- ship than of a laboratory. Marschner is impressed. He rings the bell at the back door. An employee opens, shakes his hand and grins cheerfully: “I’m Diego, come on in.” Behind them, the door clicks shut. It will be ten days until it will open again for the musician.
Sleepless in Cologne
A guitar, a barren room, lots of coffee and little sleep – the musician and student Benjamin Marschner has renounced his everyday life for ten days. The result is not a new
studio album, but a bunch of data for science. Jülich, Cologne and Zurich researchers are investigating what sleep deprivation does to us and whether coffee helps to dispel fatigue.
A visit to the sleep lab.
Tired – and now? Benjamin Marschner is not allowed to sleep, anyway. The sleep study in which he takes part specifies exactly when he may go to bed. Marschners guitar has been standing unused in the corner for two days now – the 32-year-old is feeling too tired.
Day 3
Getting accustomed
Marschner has already spent two nights at the centre. His barren room radiates little atmosphere: clinically sterile, with room only for a bed, cupboard and a computer for the tests.
“We’re only allowed in the rooms to sleep,” explains Marsch- ner. “We”, this includes himself and another study participant, with whom he spends the days in a much more comfortable lounge, playing Monopoly or watching television. Sport is not allowed, nor are nerve-racking shooter games on the PC or entertaining phone calls with friends – basically everything that dissipates fatigue. A camera monitors what is happening;
even a nap is not permitted.
“It takes getting used to spending the whole day and night in such a controlled way, but the staff and above all my ‘study parents’ are terribly nice,” Marschner says, referring to the research couple Dr. Eva-Maria and Dr. David Elmenhorst, who are both physicians. While she is doing research at DLR on sleep, her husband has specialised in molecular imaging meth- ods at the Jülich Institute of Neuroscience and Medicine (INM- 2). Apart from being married and being interested in sleep, their common intersection is a positron emission tomography (PET) brain scanner located in the DLR sleep laboratory and operated by Forschungszentrum Jülich. “This combination of sleep laboratory and imaging technology at one site is unique in the world,” explains David Elmenhorst. “Brain scans, as we create them using PET, help us to investigate the structure and function of the brain.” To make the metabolic processes visible, he injects a radioactively labelled substance, a so-called tracer, into the study participants’ bloodstream. It emits measurable radiation for about two hours and must therefore be freshly manufactured by nuclear chemists at the Jülich Institute of Neuroscience and Medicine (INM-5) and transported to DLR for each examination.
A look at the papers: in his room, Marschner studies the tasks for the next tests.
Day 4
The calm before the storm
A controlled test routine has set in. The maximum illumination is a dim 100 lux – more light would act like a pick-me-up, but the researchers want to avoid this effect. For comparison: a street light has about 10 lux, a sunny day can exceed 100,000 lux. The two test persons, fully wired, have slept through the previous nights for eight hours. “This is the adaptation phase, in which we collect all the data from our relaxed and well-rest- ed test persons; the caffeine-free status quo, so to speak, which we also measure with PET,” explains Eva-Maria Elmenhorst.
The exciting part for research begins when the test persons have to make do with less sleep. The research couple is investigating how sleep deprivation affects our performance.
Eva-Maria Elmenhorst is particularly interested in occupation- al groups working in shifts and on night duty who are exposed to special sleeping and recreational conditions: pilots, air traf- fic controllers, nurses, truck drivers or astronauts – after all, 16 per cent of the working population work shifts.
“We know that this type of work has long-term negative con- sequences on health,” says the scientist. The risk of high blood pressure, diabetes and even cancer is increasing. There also seems to be a connection with depression.
Not just scientifically of one heart and one mind: the research couple Dr. Eva-Maria and Dr. David Elmenhorst. She conducts research at the German Aerospace Center (DLR) in Cologne, he at the Institute of Neuroscience and Medicine at Forschungszentrum Jülich.
In addition, chronically tired people pose a danger to road traffic: according to the Federal Statistical Office, 2,000 accidents per year in which people are injured are caused by the driver falling asleep. “Even after one single sleepless night, driving behaviour is as impaired as after two bottles of beer,”
the doctor explains to her astonished test persons. Up until now, Marschner did not know anything about that.
The messenger substance adenosine plays a central role: its concentration in different brain regions increases during the course of the day. The longer we stay awake, the higher the concentration. Adenosine docks to certain receptors in the brain and inhibits neuronal activity. “It acts like an electric dimmer that turns the nerves from awake to tired, creating the need for sleep,” explains David Elmenhorst, who uses brain scans to investigate precisely these processes.
Sleep – the essentials in a nutshell
The longer we are awake, the higher the concentration of adenosine is in our brain. As a neuromodulator, adenosine acts like a dimmer that
puts the nerves from awake to tired. The need for sleep arises and grows in the course of the day.
Many people know it from everyday life:
we feel tired and unfocused after one single night with little sleep. “Most people react roughly as if they had a
blood alcohol of 0.6 per mille,” explains David Elmenhorst.
Surprisingly, not all people react to sleep deprivation in the same way. The studies of Eva-Maria and David Elmenhorst show: some test persons were still concentrated even after 52 hours of sleep deprivation. The scientists assume that genetic
differences in the adenosine system are responsible for this: “Contrary to our expectations, we found in the hardly affected individuals a particularly large amount of free adenosine receptors to which our radiolabeled ligand was able to attach. They probably produce
less adenosine than sensitive individuals.”
In the long term, this could lead to the development of career recommendations, as shift work is a
particular burden for some people.
performance losses – the coffee study, with 40 test persons, is intended to give an explanation.
Three cups a day, 300 milligrams of caffeine: from the fifth day onwards, the test persons receive an exact amount of caf- feine – or at least, one half of the study participants. The other half drinks decaffeinated coffee. Both varieties are provided by the cooperation partner, Institute for the Scientific Informa- tion on Coffee (ISIC), which is a research institute of the coffee industry. If used in a controlled manner, caffeine could be a suitable component of psychostimulants for all those occu- pational groups for whom being awake has top priority. “We would have to find a form of administration that works for a long time – without the known side effects such as tachycardia or increased blood pressure,” says Elmenhorst.
For Marschner, the first brain scan is due today. The tracer delivery from Jülich is already eagerly awaited, as unexpected traffic jams have sometimes caused some flurry and delays in the past. If the tracer comes too late, the exact measurement for the day will not work. But the driver arrives on time – the relief is noticeable in the Elmenhorsts. PET reveals where the labelled substance attaches to the adenosine-free receptors in the brain.
“I feel a little queasy when I think that I have been exposed to radiation for a short time,” Marschner admits. However, the scientists have explained the side effects to him extensively.
The radioactive tracer will largely be excreted with the urine.
He has to lie quietly in the scanner for two hours and answer perception, concentration and memory tests. The young man is still feeling rested. And he is also going about the upcoming night with only five hours of sleep calmly – everything is out- dazzled by the anticipation of the first coffee after more than three weeks of abstinence tomorrow morning.
Day 9
Agonising sleep deprivation
It is still early in the morning when Benjamin Marschner is woken up – he has slept a maximum of five hours at a time for five nights in a row now: “In such cases we speak of a chronic sleep deficit,” explains David Elmenhorst. Scientists now agree that 7 to 7.5 hours is the optimal “sleep dose”, bringing us through the day concentrated and in a good mood. Marsch- ner is neither in a good mood nor does he feel well-rested:
“Just don’t get up,” is his first thought. But Diego, a doctoral researcher at the University of Zurich and staff member in the sleep study, knows no mercy. Marschner is feeling knackered and unfocused. He read less and less during the week: “I can only distract myself visually,” says the Cologne native – even coffee is no longer doing any good, and he does not even know whether it contains any caffeine at all. For days, the guitar has been sitting in the lounge unused.
per year – it is thus our favourite drink
Little sleep makes you ill
Various studies have shown that short sleepers who regularly sleep for less than seven hours must expect consequences to their health and
performance. They have a 12 per cent higher risk of dying earlier. However, chronic sleep deprivation and
all-nighters are widespread in our society.
In addition to shift work and night duty, another factor that impairs sleep quality and duration is
traffic noise, for example.
Sleep deprivation leads to absenteeism from work and a decline in productivity, which is reflected
in a country’s economic performance. A study by RAND Europe, an offshoot of the Californian think tank RAND, has shown that 200,000 working days are
lost annually in Germany, which equals an economic output of € 40 billion or 1.56 per cent of the
gross national product.
Source: Tchibo Kaffeereport 2018
Off into the tube: Marschner is moved into the tomograph.
He has to lie still for the next 120 minutes, but is not permitted to fall asleep. The positron emission tomograph (PET) records biochemical and physiological processes in the brain and thus provides information on the effects of caffeine, for example.
Eva-Maria Elmenhorst uses a computer to test Marschners concentration, reaction time and working memory: he is to remember some of the letters shown to him before. and to re- act when they repeat themselves. “This allows for the current output capacity of his working memory to be compared with that of the well-rested test person,” explains the physician.
The so-called psychomotor vigilance test is a further atten- tion test, which shows very precisely whether Marschner’s subjective assessment of concentration matches his actual concentration: when a stopwatch appears on the screen, the student must instantly press a button – but sometimes he no longer registers the stopwatch at all. His reaction times slow down measurably. “While some overtired people are extreme- ly unfocused and even have blackouts, others have hardly any performance deficits – we still have to understand the connec- tions in the brain,” says the physiology specialist.
The Elmenhorst couple is particularly interested in how the maximum chronic sleep deprivation at this point in time affects the number of adenosine receptors. Therefore, the 32-year-old has to lie still again in the brain scanner for 100 minutes, which now seem endless to him. Again and again, he is almost overwhelmed by sleep – if it weren’t for the assistant’s voice that keeps him awake over the loudspeakers: “I always engage the test persons in conversations so that they don’t fall asleep,” says medical technical assistant Annette von Waech- ter – two hours of continuous entertainment, so to speak. A real challenge, but one that is worth it since researchers record crucial data during this time. The PET images are intended to show the scientists whether the brain reflects what is obvious:
Marschner needs a good night’s sleep. At 11 pm, connected by wires, he is finally allowed, for eight hours,
to escape into the realm of dreams.
Ready for the next exploration of Mars? The futuristic-looking outfit is an imaging procedure without side effects: the awake electroencephalography (EEG). The small metal plates measure Marschners brain waves, which are recorded graphically. The electroencephalogram allows conclusions to be drawn about brain activity.
57
billion euros are lost from the German economy every year
due to tired employees
Day 10
Return home
At seven o’clock on the dot, the dreams are over: Marschner is woken up. “I can’t remember much, except I fell asleep right away.” He feels more rested today and is looking forward to his last day in the lab. Once more a sampling of blood, comple- tion of the morning tests and another PET – the procedure is already routine for him. “We want to check how quickly the values of the adenosine receptors drop back to the initial level after a recovery sleep – this seems to happen surprisingly quickly. This is at least shown by the results of previous stud- ies,” says David Elmenhorst. The concentration tests are also much easier for Marschner today.
And then it’s over. When he says goodbye, he hugs his “study parents”: “They’ve really grown on me.” For the future, the musician has decided to sleep more regularly in order to stay fit – and to keep drinking coffee. Marschner opens the door to the outside: taking a deep breath – fresh air for the first time after ten days – and finally eating chocolate again.
K ATJ A L Ü E R S
Cape Canaveral 1986
Challenger
On 28 January 1986 at 11.38 am local time, the Challenger space shuttle takes off. Millions of TV viewers
watch the launch. 73 seconds later, 15 kilometres above the Atlantic, Challenger explodes. The crash of the space shuttle was partly caused by a wrong decision, which the responsible
persons had made in the early morning after less than two hours of sleep.
Alaska 1989
Exxon Valdez
On 24 March 1989 around midnigt, the oil tanker Exxon Valdez rams into a reef off the coast of Alaska. More than 40
million litres of oil flow into the sea. The accident occurred after the ship had abandoned the usual route at night to avoid
icebergs. During the detour, the captain left the rudder to his inexperienced third officer. The exhausted officer failed to
bring the ship back on its original course.
Lack of sleep with fatal
consequences
Although physics can describe the structure of atomic
nuclei very well, there is still great uncertainty about one fundamental value:
the lifespan of the neutron. With a new numerical method, Jülich researchers have now come one step closer to
solving this mystery.
a neutron live?
All atomic nuclei that make up our universe consist of protons and neutrons – in varying numbers, depending on the type of atom. If neutrons or protons occur indi- vidually, they differ in one important respect: while the free proton can exist forever or at least for an unimagi- nably long amount of time, a free neutron lives a com- parably short life before it decays. Its average lifespan lasts only about 15 minutes. Physicists cannot say how long exactly – which is unusual for the otherwise very precise scientists.
One reason is different observations: if physicists look at the disappearance of the neutrons, they get a differ- ent lifespan than if they record the occurrence of the decay products. The two measuring methods are very precise in themselves, but their results differ by well over eight seconds. For physicists, that’s an eternity.
This difference is so far not only inexplicable, but also unsatisfactory. Knowing the exact lifespan of the neutron would help to better understand the laws of the universe and to verify theoretical ideas of the big bang.
Computer simulations are intended to help in this re- spect; but: “How long a single neutron will exist cannot be predicted. Quantum mechanics, which describes this process, merely provides probabilities,” says Dr. Evan Berkowitz from the Nuclear Physics Institute/Institute for Advanced Simulation (IKP-3/IAS-4), describing the problem so far. However, Berkowitz and his colleagues have brought research an important step forward: With the help of supercomputers, they calculated, for the first time directly and as precisely as never before, how great this probability is.
“We have determined the so-called coupling constant for this purpose. It describes how easily neutrons decay due to the weak interaction, the force that can cause conversions from one type of particle to another,” ex- plains Berkowitz. “This constant is difficult to calculate with the standard model of particle physics.”
IN A NUTSHELL
The new mathematical methods used by the research- ers improve the algorithms previously used in part of the Standard Model, known as quantum chromody- namics (QCD). “In these methods, space and time are represented by points on a grid,” explains Berkowitz.
“Through this construction, a calculation of the rela- tionship between the elementary particles is funda- mentally possible – but only with the aid of powerful supercomputers.”
The method also points the way to further improve- ments that may clarify the discrepancy between measurements of neutron lifespan. For this, though, the accuracy of the calculations would have to be improved further. Evan Berkowitz says that this is basically no problem: “If someone is willing to pay the electricity bill for our complex calculations on supercomputers, we can continue to reduce the uncertainty of our response.
The electricity bill will not be cheap, however,” he warns.
J E N S K U B E
Mini universe simulated
Neutrons and protons consist of so-called quarks – the smallest building blocks of matter. The neutron is composed of two down quarks and one up quark, the proton of one down quark and two up quarks.
The quarks are held together by the gluons, a kind of particle adhesive.
When a free neutron decays, further elementary par- ticles are formed on the one hand – an electron and an antineutrino – and on the other hand, the neutron is transformed into a proton. In the world of quarks, this means that a down quark turns into an up quark.
Jülich researchers have calculated the frequency of this process in order to determine the probability of neutron decay. To do so, they have used the part of the standard model of particle physics that describes how quarks and gluons interact with each other, which is known as quantum chromodynamics (QCD).
The calculation is extremely complex, which is why the researchers only simulated a tiny model universe
with a single neutron consisting of the quarks. Even for this simplified system, they needed a powerful supercomputer.
Another problem: quantum chromodynamics says that down quarks always remain down quarks and up quarks always remain up quarks. Accordingly, a calculation with the help of QCD usually shows that neutrons are stable. “QCD is a simplification of reality, however, because it only describes the strong interaction between the particles. We must take into account that there are also small effects of the weak interaction between down quarks and up quarks – the force that allows particles to transform. That’s why we added the transformation of a down quark into an up quark to our simulation,” explains Evan Berkow- itz. This allows the researchers to determine the coupling constant and the probability that a neutron will decay.
“If someone is willing to pay the electricity bill for our complex calculations on supercomputers,
we can continue to reduce the uncertainty of our response.”
E VA N B E R KO W I T Z
Proton
Neutron
d
u u
u W -
_ Ve
e- d
d
A neutron consists of one up quark (u) and two down quarks (d). When it decays, a proton is formed. For this, a down quark of the neutron (d green) must be transformed into an up quark (u green). Another elementary particle is emitted in the process:
a negatively charged W boson (W-), which eventually decays into an electron (e-) and an antineutrino (_ Ve).
Once all the peppers have been picked, the last leg of the leaves’ and stems’
journey takes them to the compost heap. Researchers from Jülich, Aachen and Bonn don’t think that this needs to be the case. They are investigating whether valuable
substances can be extracted from the unused plant leftovers for use in medicine, cosmetics and the food industry. In the end, the vegetable farmer could profit:
he sells not only the fruit, but also the accessory agents.
Maxed out!
valuable raw materials as possible from leaves and stems.
They are crisp, fresh and healthy: bell peppers.
The fruit from the nightshade family has long since landed in salads, frying pans or on the grill in all colours all year round. It’s no wonder that farmers in Germany are growing more peppers.
Classically, they sow the peppers in the green- house, take good care of them, harvest the bell peppers and sell them. Leaves, stems and roots end up as compost. Dr. Anika Wiese-Klinkenberg from the Institute of Bio- and Geosciences (IBG-2) section finds that these are “squandered resourc- es”. In the TaReCa joint research project, the plant physiologist, together with colleagues from RWTH Aachen University and the University of Bonn, is developing technologies to utilise the
plant’s leaves and stems as well: “After the fruit harvest, we use the plant as a production factory for valuable substances known as secondary me- tabolites.” These include dyes, fragrances and fla- vourings, but also poisonous and bitter substances as well as antioxidants. Such plant constituents are particularly interesting for medicine and the cosmetics and food industries.
DELIBERATELY INDUCING STRESS
The plants use these substances to attract insects or fend off microbes such as viruses, fungi or bacteria. They produce the bioactive substances when they are, among other things, under stress such as from too much sun. “For example, plants cannot put up an umbrella to protect themselves from too much ultraviolet light and therefore form secondary metabolites that absorb the ultraviolet light,” explains Wiese-Klinkenberg.
The Jülich scientists want to produce such stress reactions in a controlled manner so that the plant produces more secondary metabolites and the residual mass from production is upgraded. The scientists already conducted initial experiments with tomato plants in a previous project of the Bioeconomy Science Center (BioSC), the research cluster for sustainable bioeconomy in North Rhine-Westphalia.
Now it’s paprika time. The Jülich researchers are initially concentrating on two of the more than 100,000 known secondary plant compounds:
the flavonoids cynaroside and graveobioside A.
“However, we also want to analyse the paprika leaves for other interesting ingredients.”
In recent years, the number of patent applica- tions involving the substance cynaroside has increased. “We therefore assume that cynaroside is an ingredient with promising market potential for the cosmetics and pharmaceutical industries,”
explains Wiese-Klinkenberg. Graveobioside A is known to act against insect egg deposition: In the long term, it could be used as a natural biocide.
In order to stimulate the production of the two substances, the scientists put the plants under stress in climatic chambers: with common salt in the nutrient solution, with low temperatures and ultraviolet light, or they deprived them of their nutrients. “The salt stress was the most effective.
Through the combination of salt addition and other stress factors such as cold, we have succeed- ed in increasing the cynaroside content in the
2 times as large . 5
as ten years ago is the area on which
paprika was planted in
Germany
in 2018
leaves tenfold. That was a surprising success,”
says the researcher excitedly. The researchers were also able to measure a triple increase in the concentration of graveobioside A in certain salt stress combinations: “We get about 20 milligrams of graveobioside A per gram of dry weight. That’s a good yield.”
The scientists are now working on improving the coordination of the interaction between optimal salt dosage, treatment duration and various stress factors, because “too much” means that the plant dies and drops its leaves, “too little” means too little yield. “In addition, the vegetable farmer also needs a measurement method to control how stress works,” says the researcher. “For this, we use non-invasive methods with photos and colour analyses as the colour of the leaves, for example, changes with the stress.”
Vegetable farmers in particular could benefit from these research approaches: they sell not only the fruits, but also the accessory agents from the rest of the plant. “In order to assess the market poten- tial of individual ingredients and possible areas of application, the TaReCa joint research project involves not only plant researchers, horticulturists and process engineers from the BioSC, but also economists,” explains Wiese-Klinkenberg. For example, they can calculate whether the farmer
should dry the leaves and stems himself or whether a large contractor should collect them:
the drying process would significantly reduce transport costs, but the vegetable farmer would have to invest in a drying oven.
TARGETING NOT ONLY PEPPERS
The peppers in the salad, the flavonoids extract- ed – what remains is the fully exploited pepper plant, which no longer ends up in the compost, but in a biorefinery, where it is converted into platform chemicals for many other industrial products and has, thus, finally completed its ser- vice. The value chain is thus extended, economic added value is generated and a valuable substance is produced in a resource-saving manner – an example of a successful bioeconomy. And this not limited to the peppers. “Long term, we want to apply the new processes and technologies to other horticultural plants,” says Wiese-Klinkenberg. Her next favourite: the cucumber.
K ATJ A L Ü E R S
TaReCa
The acronym stands for the joint project “Tailoring of secondary metabolism in horticultural residuals and cascade utilisation for a resource efficient produc- tion of valuable bioactive com- pounds”. TaReCa is funded by the Federal Ministry of Education and Research.
100 Germans on average
every year **
7.4 7.5 6.2
2.7 1.7 2.1
1.7 1.7
Cauliflower Courgette Mushrooms Asparagus Iceberg
lettuce Paprika Cucumbers Onions Carrots Tomatoes
Sources: * Agrarmarkt Informations-Gesellschaft mbH, ** Federal Ministry of Food and Agriculture
“I’m examining the movement of cells such as rod-shaped bacteria:
How do they control their forces, what controls their movement – individually and in groups – and how does the cell react when forces act on it? In my team, we search for basic principles and develop algorithms for the cross-scale description of cellular mechanics, from the signal molecule
to the whole cell. Our findings help to understand how organisms grow, i.e. how ordered structures develop from individual cells during cell division or how tumours spread.”
Dr. Benedikt Sabass, Head of Young Investigators Group at the Institute of Complex Systems, Theoretical Soft Matter and Biophysics division (ICS-2/IAS-2)
What are you researching right now, Mr Sabass?
T
he first driving lesson in heavy traffic: at an intersection without traffic lights, there are four cars looking in different directions, and one cyclist. What the driving instructor sees at a glance causes the learner to break out in sweat. Obvious- ly, the driving instructor is an expert in road traffic matters, the learner an inexperienced beginner. Can you tell by the external reaction alone? That’s not enough for brain research- ers. They want to know how different levels of experience are reflected in the brain. An ancient but highly complex game helps them to find this out: chess.Dr. Robert Langner from the Jülich Institute of Neurosciences and Medicine (INM-7) explains why this particular board game is suitable for brain research: “Chess is based on clearly defined rules that are easy to grasp and has a limited num- ber of pieces. At the same time, however, the game is highly complex, like real life.” In addition, there is an established and objective mathematical method to precisely determine the expertise of a chess player, the so-called Elo score. This rating score makes it possible to establish a direct connection between level of expertise and activity in the brain. A look into the brain, then, reveals clear differences: unlike novices, ex-
perienced players use not only one half of the brain, but both.
For example, a certain temporal region on the right side is only activated by experts. “We were able to show that this region is efficiently integrated into other brain networks. In this way, relevant information about the game situation and the possible moves of individual objects can be processed and evaluated quickly and comprehensively,” says Langner.
RECOGNIZING PATTERNS AT A GLANCE
How effective this wiring must be in the brain of experienced players can be seen in blitz chess. In fractions of a second, they grasp the situation on the board and make a meaningful move.
When comparing the eye movements of experts and beginners in such situations, another difference becomes clear: chess experts focus their gaze only on single, strategically important pieces. Through years of practice and replaying games, they recognize game-specific patterns and spatial connections on the board and know almost “instinctively” where they have to look to solve a situation. Looking at chess novices, the gaze wanders over a multitude of pieces, even those that have nothing to do with the next move. Functional magnetic resonance imaging showed that areas involved in the recog- nition of objects and also for spatial connections are activated
For the researchers around Robert Langner, chess is more than just a game:
they use it in brain research to investigate paradigmatically how the brains of novices and experts differ.
better connected
If the brain is trained to recognize patterns, even proven experts can sometimes be blocked from seeing something new. In a chess puzzle for advanced players, the psychologist Prof. Merim Bilalić, himself a chess master, placed the pieces in such a way that a checkmate could be achieved with a common five-move strategy. A checkmate in the same situation would just as well be possible with a widely un-
known solution in only three moves. If the eyes of the chess players recognized the familiar pattern of the five-moves solution, they concentrated on it and were literally blind to the faster variant.
Here, scientists speak of the “set effect”, which can also limit the judgement of other specialists such as lawyers, doctors or personnel specialists. Studies show that
radiologists, for example, often concen- trate on the first irregularity that catches their eye. At the same time, other signs of a disease may be overlooked, such as swelling, which may indicate a tumor. In the chess experiment, only grandmas- ters – i.e. experts with enormous experi- ence – were able to recognize the shorter three-move solution to the checkmate.
Practice makes perfect
more strongly in the brains of experienced chess players than in those of novices. “Purposeful perception also plays an im- portant role in everyday situations,” says the psychologist. “For example, the experienced driver recognizes the stop sign and knows that the car coming from the left or right now has right of way, without giving it a long thought.” Skilled visual percep- tion is driven by certain patterns and spatial regularities, both in experienced chess players and in experienced road users. “If the stop sign was placed in a completely unexpected position, it would most likely be overlooked,” says Langner.
WHEN ROUTINE IS NOT ENOUGH
Even chess experts can get confused. Experiments carried out by Langner’s colleague Prof. Merim Bilalić at the University of Tübingen have shown that if the chess pieces are spread out on the board without any concept, the eyes of experts meander across the random arrangement as do those of the novices. The situation will be similar even for the most experienced Euro- pean drivers if they find themselves in the chaos of an Indian crossroads. “ ‘Chaos’, however, is relative,” Langner interjects.
“The situation is chaotic only for those who don’t know the local rules.”
The observation of chess players could also help to understand how the brain works in other challenges. “In chess, it is not only important to grasp the current game situation and plan the next moves, it is also important that the players put them- selves into the opponent’s position,” says the Jülich scientist.
For example, he and his colleagues are interested in whether chess is suitable for neuroscientific studies of social phenom- ena, such as interactions with other people or recognizing the intentions of a counterpart. “To our knowledge, using chess in this context is completely new territory,” says Langner.
B R I G I T T E S TA H L-B U S S E
Few pieces, clear rules, yet chess is highly complex.
Novices play much worse than experts. This is ideal
for brain researcher Robert Langner to find out how different levels of experience are reflected in the brain.
Accra, Ghana, on a morning with 30 degrees Cel- sius outside temperature and 80 per cent humid- ity: in the surrounding gardens, residents water their vegetables and loosen the soil before the humid midday heat will later force them all into the shade or the houses. In the air-conditioned building of WASCAL, the competence centre for climate change and sustainable land manage- ment, “ground work” is carried out by means of data: bent over a phalanx of laptops, 30 young Af- rican scientists use computer models to simulate
the ground-water-air system at supercomputer level. The training in the Ghanaian capital is the highlight of the project “The Pan-African Soil Challenge”, PASCAL for short.
“The idea behind PASCAL is to build a scientific bridge between Forschungszentrum Jülich and partners in Africa,” says Dr. Daniel Felten from the Jülich Institute of Bio- and Geosciences (IBG-3), who coordinates the project. In view of the popu- lation explosion and of climate change, the aim is
The climate is changing, the population is growing, Africa is facing great challenges.
Scientific exchange can help: the PASCAL project is designed to support the people there in securing their nutrition in the long term. The highlight so far has been a
project week with an autumn school in Accra.
A bridge to Africa
Award for PASCAL
At the end of 2017, the German Research Foundation (DFG) awarded PASCAL a first prize in the category “Research mar- keting”. The largest part of the prize money of € 100,000 went to the project week in Accra in late 2018.
do research in Jülich in summer 2018 and to re- port there on the autumn school and hackathon.
With the blog “A Bridge to Africa” and in the social media, participants sup- ported the project from the very beginning.
to support Africa in developing safe and sustain- able food production. “By 2050, Africa’s popula- tion is expected to double to 2.5 billion people.
Providing them with sustainable food will be a great challenge,” says Felten. Jülich’s expertise in soil science and in high-performance computing could be of use here in order to increase the yield of fields on this basis, for example.
Also on board is Geoverbund ABC/J, the geo- scientific network of RWTH Aachen Universi- ty, the universities of Bonn and Cologne, and Forschungszentrum Jülich. Felten: “It is impor- tant to us that the participants pass on the newly acquired knowledge, thus becoming multipliers.”
A total of 173 young scientists from 23 African countries had applied to take part in the autumn school and a so-called hackathon – a workshop in which people work together to advance and improve software. “We were able to offer around 30 applicants a place for one or both training courses,” explains Felten.
Jülich’s agrosphere research and Geoverbund ABC/J are continuing their commitment to Afri- ca. At an “Africa Day” at the University of Bonn
in the second half of 2019, the two partners want to present projects from research on the earth’s system. Another holiday school in Africa is also being discussed. The bridge is getting sturdier.
E R H A R D Z E I S S
“This program is a
good solution to help African universities improve more quickly.
If the program can take place more than one time a year and cover many other fields,
it will be quite great.”
F R A N C I S O U S S O U F R O M B E N I N ,
PA R T I C I PA N T I N T H E PA S C A L A U T U M N S C H O O L I N G H A N A
You can find more pictures of the Accra workshop in our web magazine.
Blog “A Bridge to Africa” with person- al impressions and interviews with the participants:
blogs.fz-juelich.de/
bridgetoafrica
i
Imagine you could use the online shopping on your smartphone not only to see a sofa, but also to feel the fabric cover, or a blind person could palpate a Braille text on his touch screen. Com- panies are working on making haptic displays of this kind ready for series production.
But how can a smooth display suddenly make a structure like Braille palpable? It does so with a trick: the nerve cells on our finger are tricked into feeling that the surface is changing. The physicist Bo Persson from Jülich has worked in- tensively on the physical basics: what is essential are the frictional forces that are at work when the finger slides over the display. Nerve cells in the finger perceive tiny differences in these forces as if they were unevenness. Persson has developed a computer model that can calculate these forces – the basis for understanding how the tactile sense can be influenced. The model predicts, for example, how friction and thus the tactile sense will change if, for instance, the fin- ger is damp or strokes the display very forcefully.
“It is important to bear in mind that the fingertip is not smooth. This means that the contact be- tween the fingertip and the display must be taken into account on a wide range of length scales, from nanometres to millimetres,” says Persson.
The fact that Persson’s model correctly describes the interaction between finger and display has been proven by his cooperation partners from Turkey: their experimentally measured values correspond well with the predictions of the Jülich physicist.
F R A N K F R I C K
supposed to make this possible. The physicist Bo Persson has packed the physical
basics for this into a computer model.
How the touch screen works
A haptic display consists of three layers: on a glass plate lies an electrical conductor and above it an electrically insulating material. The finger only touches the top layer, the insulator. If an electrical voltage is applied to the carrying layer, opposite electrical charges accumulate on the insulator and on the finger (picture 1). The consequence: the display attracts the finger electrostatically. The greater the voltage, the more the finger is pressed against the display – and the greater the slid- ing friction. This way, different voltages at different points in the display can be used to simulate different surface structures in the tactile sense.
In all cases, however, a trick is required to ensure that the electrostatic attraction is maintained long enough to be felt.
Picture 1, therefore, shows a snapshot as the electrical charges from the fingertip migrate to the display surface, thus reducing the attraction. To prevent this, the voltage of the carrying layer is reversed approximately 100 times per second. This is so fast that our tactile sense does not perceive this polarity reversal. It only registers the average strength of the tension.
At the same time, an electronic circuit has to detect where ex- actly the finger is gliding over the surface – a technology that is also used in conventional smartphone displays. The control electronics then vary the strength of the voltage at the respec- tive spots (picture 2), simulating the desired surface – from the sofa cover to the Braille text.
Bo Persson has specialised in the physical fundamentals of friction. Friction also plays an important role in touch screens.
Insulat or Transpar
ent conduc
tor Glass plat
e Picture 1
Picture 2
Insulator
Transparent conductor with variable alternating voltage Glass plate
Alternating voltage
There is a flash of light when a neutrino interacts with the special liquid inside the detector. “Neutrinos, electrically neutral and extremely light elementary particles, are produced, for example, during reactions in the core of the sun,” explains Jülich physicist Prof. Livia Ludhova, one of Borexino’s two scientific coordinators. Billions of solar neutrinos fly through every square centimetre on earth every second – even through our bodies – but the particles can hardly be detected. This is due to their weak interaction with matter. Reactions that lead to the flashes of light are extremely rare. In order not to miss any of the rare flashes, some 2,000 highly sensitive light sensors are arranged around the Borexino tank, which is filled with 280 tons of a special liquid called “scintillator”.
Furthermore reactions of other particles could interfere with the measurement: the natural radioactivity of ordinary mate-
rials would cause a billion times more flashes than the solar neutrinos, so the Borexino detector had to be constructed of low-radiation materials. The scintillator itself consists of the lowest-radiation liquid ever produced. The so-called cosmic rays, which continuously patter down on the earth from outer space, would also produce far more light flashes than the neu- trinos. But the mountain massif with its 1,400 metres of rock above the measuring chamber almost completely shields these particles – only the neutrinos can pass the rock unhindered.
NEW MEASUREMENTS
Neutrinos are the perfect messengers and the only direct proof of the processes inside the sun: the nuclear fusion reactions that make our central star shine and are thus an essential prerequisite for life on earth. Deep inside the sun, hydrogen atom nuclei fuse to form helium in various reaction paths,
Exploring the inside of the sun deep under the earth? Sounds like a paradox.
But this is exactly what scientists have been doing since 2007 in an underground laboratory in the Gran Sasso massif not far from Rome: in the Borexino experiment, they observe
rare flashes of light in a unique detector. The measured data provides new insights into the reactions powering our sun.
Solar telescope underground
Inside the Borexino tank:
around 2,000 highly sensitive light detectors were installed on the the inner wall of the stainless steel sphere to detect neutrinos.
generating not only solar energy but also neutrinos. “We have now evaluated the latest data from 2012 to 2016, the so-called Phase 2 of the Borexino experiment. In this phase, we further reduced the radioactive radiation of the liquid scintillator and for the first time observed the entire energy spectrum of the solar neutrinos. Our results provide new and more precise information about various processes in the sun’s interior,”
Ludhova says.
For the first time, the researchers have succeeded in observ- ing neutrinos from four different branches of the so-called pp fusion chain in one single measurement. These include neutrinos from the so-called pep reaction, which have now been unequivocally proven. The results confirm the scientists’
general understanding of energy production in the sun. “The data with unprecedented accuracy is invaluable for us to fur- ther specify the so-called standard solar models, that is, our knowledge of the chemical composition of the sun,” reports the Jülich expert.
BALANCED FOR THOUSANDS OF YEARS
Yet another discovery was hidden in the data as well: “We can read the sun’s current energy production in its interior from the neutrinos that reach the earth – with only eight minutes delay.” That is how long it takes neutrinos to travel to the earth at almost the speed of light. The light and heat of the sun, on the other hand, take about 100,000 years to travel from the core to the surface of the plasma ball and from there to the earth. The comparison of the information from the neutrinos with the data from light and heat showed: energy production has not changed during this period. According to Ludhova:
“So the sun has been in equilibrium for at least 100,000 years.”
Hence, mankind certainly does not have to fear that the ener- gy production of the sun will change dangerously or that the sun is even “consumed” in the next millennia.
J E N S K U B E
The sun is a gigantic fireball of hot gases and the birthplace of neutrinos. It has a diameter of just under 1.4 million kilometres, which is about one hundred times that of the earth (12,700 kilometres). The core of the sun has temperatures of around 15 million degrees Celsius.
Fusion reactions in the nucleus produce energy – and vast amounts of neutrinos, electrically neutral elementary particles with a very low mass. While light and heat struggle to make their way through the different layers of the sun, neutrinos can cross them almost unhin- dered. This is because neutrinos hardly interact at all with other matter. Once the neutrinos have left the sun, they race through space at almost the speed of light.
Neutrino factory
Core
Photosphere
Solar atmosphere
Neutrinos
Anyone who is new may also break new ground. This was apparently the idea of the Helmholtz Center for Information Security
(CISPA), which was founded at the beginning of 2019. On Facebook, the experts for cyber security published a music video in which the artist EstA presents the Saarbrücken-based centre in a rap. However,
CISPA was not the first research institution with a rap song:
The Large Hadron Rap of the large-scale research facility CERN in Switzerland has been available on YouTube since 2008,
with scientists picking up the microphone themselves.
– W W W. FA C E B O O K .C O M /C I S PA S A A R L A N D – – Y O U T U B E , K E Y W O R D : L A R G E H A D R O N R A P –
CISPA R A P
Helmholtz Center introduces itself
We expect up to 20,000 visitors at Forschungs- zentrum Jülich at our “Open Day” on 7 July 2019.
The topic: a journey into the future. All those who are enthusiastic about science are welcome. In their labora- tories on the Jülich campus, researchers show where the
journey is heading: for example, by presenting experi- ments and large-scale equipment with which they can look into the world of tomorrow. There’s also the chance
for participation: in a campus rally, children and youth become little researchers themselves.
Admission is free.
– W W W.TA G D E R N E U G I E R . D E – – #TA G D E R N E U G I E R –
J O U RNE Y IN TO T HE F U T U RE
We invite you to Open Day
THUMBS UP
Networking via social media is also worthwhile for scientists.
Practical tips on how researchers can use Twitter, Facebook and the like for themselves are given in the article “How to use
Twitter to further your research career”, which appeared on nature.com. Twitter, for example, is a good way to bring new releases or changes in the team directly into the community, according to the author Jet-Sing M. Lee. The short news ser- vice also offers the opportunity to contact researchers directly
and thus serves as a “gateway” to science for laypersons.
– W W W. N AT U R E .C O M /A R T I C L E S / D 4 1 5 8 6 - 0 1 9 - 0 0 5 3 5 -W –
T H AT ’S H OW I T WO RKS
Scientists on Twitter
Dr. Martin Schultz
developed the web tool with colleagues from the Jülich Super- computing Centre and the Institute of Energy and Climate Research (IEK-8). It uses official data from the German Environ- ment Agency and shows the annual average NO2 concentration for each measuring point in Germany. If the value is too high, the calculator determines the necessary reduction of road traffic emissions to comply with the limit value. stickoxid-rechner.de
